Simulation devices have been used for many years for operator training and procedure definition. In particular, simulators for power plant control rooms including plant specific replicas of control consoles for nuclear and fossil fuel power plants are developed either when a new plant is being installed or the plant owner requires simulator training for its operators. An effort is made to make each simulator as realistic as possible so that operators for the actual plant can be trained in normal operating procedures and can learn to react to abnormal plant conditions.
The power plant control room simulators are usually computer-controlled with the computer interfacing with the control console to control meters, switches, and lights on the console in a manner mimicking the operation of an actual power plant. Thus, by appropriately programming the computer, operators can be trained in all aspects of plant operation in real time.
Both nuclear and fossil fuel power plants are far too expensive, complicated, and potentially hazardous to permit on-the-job training. The transition of a plant from start-up through partial and full operation takes a considerable amount of time and is an expensive process. It is too expensive to start up and shut down a plant simply for the purposes of operator training. In addition, operators must be trained to recognize and to respond to malfunctions and emergency conditions. It is far too hazardous both to surrounding communities and personnel and to the physical plant to duplicate emergency conditions in a real time manner for training purposes. Thus, it is important that realistic simulators be developed to train operators thoroughly when possible in advance of plant completion or to retrain operators periodically.
There are many areas in a fossil fuel power plant which must be under continual monitoring and, therefore, it is important to simulate these areas. Among these are the flame characteristics in the actual furnace or firebox of the power plant, the water level in the steam drum associated with a power plant, and visible emissions given off by the power plant.
The flame characteristics in a furnace or firebox is an important indicator of the stability of a fossil fuel power plant. The furnaces are designed to support an evenly distributed fireball with complete combustion of the fuel. In addition, in a fossil fuel plant, the furnace can include multiple levels of associated igniters and fuel supplies. For example, a fossil fuel power plant may have three levels of fuel supplies or inlets with each level including one or more oil igniters and oil supply guns for raising the temperature of the furnace to the optimum level for efficient combustion of the particular type of coal being burned in the plant. The ignition of the oil from the various oil supply guns and the results of adding coal to the furnace all have associated normal visual effects. For example, initially the interior of the furnace is black and the ignition of the oil from the various oil supply guns resembles a sequence of torch flames appearing against the black background of the furnace. The flame pattern has specific characteristics including a swirling motion due to updraft of the furnace. The igniters are normally lit and the corresponding oil supply guns are normally opened in a predetermined sequence progressing from the lower or first level upward through the various levels in the furnace before any coal is added. The purpose of the igniters and oil supply guns is to raise the temperature of the furnace and to provide flame stability at low firing.
Many of the furnaces of actual fossil fuel power plants include a video camera located in the furnace above the igniters and fuel inlets. The camera transmits video images of the firebox to the control console of the plant to enable the plant operator to inspect the flame in the firebox visually. The use of a video camera, however, has not proved entirely satisfactory because carbon and other emissions given off during combustion accumulate on the camera lens with the result that the visual images become less distinct and finally can no longer be obtained. Such cameras are then rendered essentially useless until the power plant is shut down for cleaning at which time the lenses are cleaned and the cycle restarted.
Since it has proved exceedingly difficult to get video images of a firebox in operation, fossil fuel power plant simulators have not included visual simulation of the firebox. Also, if the plant operators must be trained in advance of startup of the actual power generation it may not be possible to use the in-plant camera to take training pictures.
Another condition of a fossil fuel power plant which is closely monitored is smokestack emission. The smokestack emissions serve as barometers with regard to the efficiency of the operation of the power plant and are affected by changes in the content of the fuel as well as by changes in the combustion environment within the firebox. Such changes in the firebox can result from faulty igniters, oil supply guns, or fuel feeds.
The emission content also depends upon the type of pollution equipment and the effectiveness of the pollution equipment used in conjunction with the power plant. Thus, a fossil fuel power plant will normally be equipped with scrubbers, precipitators, etc., to remove noxious gases and particulate material from the emissions from the smokestack. Generally speaking, the more opaque the emission plume given off by the smokestack the more likely that the emissions are harmful and that some corrective measure must be taken. A trained operator can determine abnormal operating conditions merely by visually inspecting the plume of the smokestack.
In actual fossil fuel power plants, it has been common for mirror or periscope systems to be used to view the plume of the power plant from the control console. More recently, television monitors with a camera aimed at the top of the smokestack have been used to provide visual images of the plume to the operators at the control console. It has not been the practice, however, to provide such visual images of the emissions of the smokestack in a control console of a simulator of a fossil fuel power plant. This, in part, is the result of the expense and risk of creating abnormal conditions in the firebox of the power plant to provide a range of emission patterns sufficient to provide a meaningful training vehicle for power plant operators. It simply cannot be justified to discharge noxious material from a smokestack of a power plant merely to obtain a visual recording of what such noxious emissions actually look like.
Another condition which is extremely important to the safe and efficient operation of a fossil fuel power plant is the water level in the steam drum. When the power plant is in a shut-down condition, the steam drum is, like the rest of the plant, cold and as a result, the drum contains only water. As the power plant is brought into operation and becomes fully operable the water in the steam drum is heated significantly with the result that steam is generated within the drum. The steam is dried and supplied to a turbine to generate power.
Most steam drums have an optimal level for the water/steam interface. In other words, the volume of water within the steam drum should not exceed a particular range in order to insure safe and efficient operation. If the water within the steam drum becomes sufficiently hot such that it all turns to steam then an extremely dangerous situation could result, such as massive wall failure causing major safety hazards to personnel and to the power plant itself.
As a result of the importance of the level of water/steam interface in the steam drum, the steam drum comes equipped with a steam drum level indicator which functions as a second indication for the operator's use. In an actual power plant, the steam drum level indicator has been viewed either directly by personnel located away from the control console or by personnel at the console through mirrors or periscopes. In any event, fossil fuel power plant simulators have not included the facility for simulating the video monitored level indicator of the steam drum. Thus, it has not been possible to visually demonstrate the effect changes in operating parameters of the power plant, e.g., changes in the fuel supply to the firebox, will have on the water level in the steam drum. This has resulted in operators being insufficiently trained to recognize dangerous conditions in the steam drum.